Abstract: A thermodynamic analysis on the reduction of fluorapatite in different systems was conducted by using the FactSage 6.4 thermochemical software. The effects of some components of high-phosphorus oolitic iron ore on the reduction of fluorapatite were studied. Results show that under non-additive condition， the defluorination of fluorapatite can be initiated at 1174℃ to produce Ca₃(PO₄)₂ and CaF₂; fluorapatite can be reduced to CaF₂， CaO and P₂ by carbon at 1439℃. CaO has no direct effect on the reduction of fluorapatite， while the minimum thermodynamic reduction temperatures of fluorapatite can be decreased by SiO₂， Al₂O₃ and Fe from 1439℃ to 1204， 1247 and 1277℃ respectively， which can facilitate the reduction process of fluorapatite. The thermodynamic results obtained are in good agreement with the available experimental results in the literatures， which indicates that thermodynamic analysis can be used to study the reduction characteristics of phosphate ore.

Key words: fluorapatite, reduction, additives, FactSage 6.4, thermodynamic analysis